The practice of controlling the temperature of a building by circulating water has been known since the times of the Roman Empire. Archeological reconstruction has revealed that bath houses often used wood-fired boilers to heat water. The hot water was then used not only in the bath itself, but was as well circulated in sub-floor conduits to heat the floor of the bath house.
Modern hydronic systems, although based on the same concept, incorporate heating, circulation, and control arrangements that would have been unimaginable to the ancients. For example, U.S. Pat. No. 5,390,660 to Danielson is directed to a pre-wired and pre-plumbed module for connection to an installed hydronic radiant floor heating system including a supporting frame having components mounted thereon such as a boiler, pumps, four-way valve, in-line air separator, expansion tank, P/T ports, return valves, supply valves and control panels mounted thereon. The module is assembled at the factory and is tested at the factory to ensure that the components are properly plumbed and wired. Once the module is delivered to the job site, the components of the module are quickly and easily connected to the hydronic radiant floor heating system.
U.S. Pat. No. 4,907,739 to Drake discusses a radiant heating system especially useful for floor heating is provided with a fluid flow apparatus that includes means for pumping a fluid such as water, a temperature-responsive actuator and a valve positionable within a valve housing in response to measured fluid temperature. The system includes heat transfer means, typically a tube embedded in the floor that receives heated fluid from the flow apparatus which in turn receives fluid at generally a higher temperature from a fluid heating apparatus such as a water boiler. The amount of heated fluid recirculated to the heat transfer means is controlled by the position of the valve in the valve housing.
U.S. Pat. No. 4,770,341 to Drake sets forth a manifold which is useful in receiving a heated liquid such as warm water from a suitable source and for distributing that liquid to a plurality of floor heat exchangers and for receiving liquid from the heat and returning that liquid to the source. The manifold includes a plurality of separate manifold elements that can be stacked adjacent one another, each element having a first and second chamber. The first and second chambers of the elements together define first and second distribution vessels within the manifold. Each manifold element includes inlet and outlet ports communicating with the respective distribution vessels for carrying liquid to and from the heat exchangers. The manifold elements desirably are integrally formed from plastic or other material exhibiting a coefficient thermal conductivity of less than 1.0 kcal/M h° C.
U.S. Pat. No. H239 to Franklin is directed to a hydronic heating system that includes a tube or series of tubes placed on modular composite panels. The panels are fabricated with a grooved surface to permit the flush embedment of the tubes on the panels.
U.S. Pat. No. 6,345,770 to Simensen, the specification of which is incorporated by reference herein, discusses a modular manifold adapted for use with hydronic circulation systems including a plurality of first and second thermal exchange zones having respective zone supply and zone return lines. The modular manifold includes a plurality of modules, each of which includes a selectively actuatable fluid control mechanism having an inlet and an outlet. The outlet of each selectively actuatable fluid control mechanism is in fluid communication with a respective zone supply line of the zone of the hydronic circulation system. Each module further includes a common return conduit section secured to the selectively actuatable fluid control mechanism. A common supply conduit section is secured to the selectively actuatable fluid control mechanism of each module. The common supply conduit section is in fluid communication with the inlet of the selectively actuatable fluid control mechanism, The modules are adapted and constructed to be connected together, with the collective common return conduit sections fitting together to form a common return conduit in communication with the return lines of the thermal exchange zones, and the collective common supply conduit sections fitting together to form a common supply conduit. The selectively actuatable fluid control mechanisms can be provided as any suitable control mechanism, such as zone pumps or zone valves. A connecting conduit having a first end connected to the common return conduit and a second end connected to the common supply conduit can be provided in the form of a U-bend. An injection mechanism having an inlet connected to a source of thermal exchange fluid and an outlet connected to the connecting conduit can also be provided. The injection mechanism can be provided as an injection pump or an injection mixing valve. A temperature gauge can be connected to the connecting conduit at a location downstream from the injection mechanism outlet. The temperature gauge indicates the temperature of fluid flowing into the common supply conduit. Tee connectors can be provided to connect the modules together, and can include a return inlet conduit connected to the zone return line of the first thermal exchange zone.
Although these arrangements offer some advantages over standard heating and cooling systems, many are complex and expensive. Even the most advanced modular systems require special castings or other adaptations to mount standard flow control mechanisms. It can be seen from the foregoing that the need exists for a simple, inexpensive modular manifold system that provides fabrication and installation advantages, overcoming the deficiencies of known arrangements.